X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fvideo%2Ffb_defio.c;h=59df132cc3756deda96bfcce5d453a309e803a15;hb=6c118e43dc513a7118b49b9ff953fe61e14515dc;hp=0f8cfb988c901a7f45314387149a759d8b252929;hpb=8755e568250ecd3149ecd3495d8070f3a5384f73;p=linux-2.6

diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
index 0f8cfb988c..59df132cc3 100644
--- a/drivers/video/fb_defio.c
+++ b/drivers/video/fb_defio.c
@@ -4,7 +4,7 @@
  *  Copyright (C) 2006 Jaya Kumar
  *
  * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file COPYING in the main directory of this archive
+ * License. See the file COPYING in the main directory of this archive
  * for more details.
  */
 
@@ -31,7 +31,7 @@ static int fb_deferred_io_fault(struct vm_area_struct *vma,
 	unsigned long offset;
 	struct page *page;
 	struct fb_info *info = vma->vm_private_data;
-	/* info->screen_base is in System RAM */
+	/* info->screen_base is virtual memory */
 	void *screen_base = (void __force *) info->screen_base;
 
 	offset = vmf->pgoff << PAGE_SHIFT;
@@ -43,6 +43,15 @@ static int fb_deferred_io_fault(struct vm_area_struct *vma,
 		return VM_FAULT_SIGBUS;
 
 	get_page(page);
+
+	if (vma->vm_file)
+		page->mapping = vma->vm_file->f_mapping;
+	else
+		printk(KERN_ERR "no mapping available\n");
+
+	BUG_ON(!page->mapping);
+	page->index = vmf->pgoff;
+
 	vmf->page = page;
 	return 0;
 }
@@ -65,6 +74,7 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
 {
 	struct fb_info *info = vma->vm_private_data;
 	struct fb_deferred_io *fbdefio = info->fbdefio;
+	struct page *cur;
 
 	/* this is a callback we get when userspace first tries to
 	write to the page. we schedule a workqueue. that workqueue
@@ -74,7 +84,24 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
 
 	/* protect against the workqueue changing the page list */
 	mutex_lock(&fbdefio->lock);
-	list_add(&page->lru, &fbdefio->pagelist);
+
+	/* we loop through the pagelist before adding in order
+	to keep the pagelist sorted */
+	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
+		/* this check is to catch the case where a new
+		process could start writing to the same page
+		through a new pte. this new access can cause the
+		mkwrite even when the original ps's pte is marked
+		writable */
+		if (unlikely(cur == page))
+			goto page_already_added;
+		else if (cur->index > page->index)
+			break;
+	}
+
+	list_add_tail(&page->lru, &cur->lru);
+
+page_already_added:
 	mutex_unlock(&fbdefio->lock);
 
 	/* come back after delay to process the deferred IO */
@@ -138,11 +165,20 @@ EXPORT_SYMBOL_GPL(fb_deferred_io_init);
 
 void fb_deferred_io_cleanup(struct fb_info *info)
 {
+	void *screen_base = (void __force *) info->screen_base;
 	struct fb_deferred_io *fbdefio = info->fbdefio;
+	struct page *page;
+	int i;
 
 	BUG_ON(!fbdefio);
 	cancel_delayed_work(&info->deferred_work);
 	flush_scheduled_work();
+
+	/* clear out the mapping that we setup */
+	for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {
+		page = vmalloc_to_page(screen_base + i);
+		page->mapping = NULL;
+	}
 }
 EXPORT_SYMBOL_GPL(fb_deferred_io_cleanup);